a.&nbspThe vascular cambium gives rise to the outer barkb.&nbspThe

a. The vascular cambium gives rise to the outer barkb. The vascular cambium gives rise to secondary xylem toward the outside of the stem and secondary phloem toward the inside of the stemc. Sieve-tube members of the phloem contain a nucleus and direct the activities of the companion celld. The cork cambium and the vascular cambium both give rise to secondary tissue.e. The P-protein in the xylem prevents the water and mineral conducting tubes from breaking during water transport